Update configuration and enhance newsletter generation features

- Change WIKI_API_URL in .env.example and config to point to the new API endpoint.
- Set COOKIE_SECURE to false for local development in .env.example and config.
- Improve the newsletter generation logic to handle new and edited articles separately.
- Add display options for showing date, user, and category in the newsletter output.
- Enhance error handling for Wiki API requests and update templates for better user feedback.
- Update CSS for new UI elements and improve overall layout in dashboard and login pages.

app/static/js/newsletter.js

@@ -0,0 +1,83 @@
+function setCopyStatus(message, isError) {
+    const status = document.getElementById("copy-status");
+    if (!status) return;
+    status.textContent = message;
+    status.className = isError ? "copy-status error" : "copy-status success";
+}
+
+async function copyForOutlook() {
+    const htmlSource = document.getElementById("newsletter-html-source");
+    const plainSource = document.getElementById("newsletter-plain-source");
+    if (!htmlSource || !htmlSource.value.trim()) {
+        setCopyStatus("Bitte zuerst einen Newsletter generieren.", true);
+        return;
+    }
+
+    const html = htmlSource.value;
+    const plain = plainSource ? plainSource.value : "";
+
+    try {
+        if (navigator.clipboard && window.ClipboardItem) {
+            await navigator.clipboard.write([
+                new ClipboardItem({
+                    "text/html": new Blob([html], { type: "text/html" }),
+                    "text/plain": new Blob([plain], { type: "text/plain" }),
+                }),
+            ]);
+            setCopyStatus("Newsletter mit Hyperlinks kopiert. In Outlook mit Strg+V einfügen.");
+            return;
+        }
+    } catch (err) {
+        console.warn("Clipboard API failed, using fallback.", err);
+    }
+
+    const container = document.createElement("div");
+    container.innerHTML = html;
+    container.style.position = "fixed";
+    container.style.left = "-9999px";
+    document.body.appendChild(container);
+
+    const range = document.createRange();
+    range.selectNodeContents(container);
+    const selection = window.getSelection();
+    selection.removeAllRanges();
+    selection.addRange(range);
+
+    let ok = false;
+    try {
+        ok = document.execCommand("copy");
+    } finally {
+        selection.removeAllRanges();
+        document.body.removeChild(container);
+    }
+
+    setCopyStatus(
+        ok ? "Newsletter mit Hyperlinks kopiert. In Outlook mit Strg+V einfügen." : "Kopieren fehlgeschlagen.",
+        !ok
+    );
+}
+
+async function copyHtmlSource() {
+    const htmlSource = document.getElementById("newsletter-html-source");
+    if (!htmlSource || !htmlSource.value.trim()) {
+        setCopyStatus("Bitte zuerst einen Newsletter generieren.", true);
+        return;
+    }
+    try {
+        await navigator.clipboard.writeText(htmlSource.value);
+        setCopyStatus("HTML-Quelltext kopiert.");
+    } catch (err) {
+        setCopyStatus("Kopieren fehlgeschlagen.", true);
+    }
+}
+
+document.addEventListener("DOMContentLoaded", () => {
+    const htmlSource = document.getElementById("newsletter-html-source");
+    const frame = document.getElementById("newsletter-preview-frame");
+    if (htmlSource && frame && htmlSource.value.trim()) {
+        frame.srcdoc = htmlSource.value;
+    }
+
+    document.getElementById("copy-outlook-btn")?.addEventListener("click", copyForOutlook);
+    document.getElementById("copy-html-source-btn")?.addEventListener("click", copyHtmlSource);
+});